1. Field of the Invention
The present invention relates to an imaging apparatus having light source identification and image quality correction functions, and a method for controlling the imaging apparatus.
2. Description of the Related Art
Imaging apparatus operations include a technique for identifying a lighting environment of the subject and performing image quality correction including white balance adjustment according to the lighting environment.
Japanese Patent Application Laid-Open No. 2007-110485 discusses a method for identifying a fluorescent lamp and a mercury lamp based on a light quantity ratio of a green light detection element (green element) and a monochrome light detection element (monochrome element). This method utilizes the fact that the effect of the green light emission intensity on the bright line spectrum differs between the fluorescent lamp and the mercury lamp.
Japanese Patent Application Laid-Open No. 2006-146081 discusses a method for identifying light sources based on the light quantity ratio of the light-extinction state using an electrochromic (EC) element to the non-light-extinction state (normal state). When a voltage is applied, the electrochromic element enters a colored state and performs a band-cut function on transmitted light in a specific wavelength range. When a voltage having the opposite polarity to the voltage in the colored state is applied, the electrochromic element enters a color-fading state and loses the band-cut function. The method performs band-cutting to acquire wavelength information of light sources, and discriminate an A light source (halogen lamp) and a fluorescent lamp.
However, all of the above-described conventional light source identification methods deals with identification target light sources having a large full width at half maximum (100 nm or more), and bright-line light sources having a full width at half maximum of about 3 to 30 nm is not imagined as identification targets.